Endoscopic transesophageal biopsy in the posterior mediastinum using submucosal tunneling technology and novel homemade instruments.

BACKGROUND/AIMS: This animal study was performed to evaluate the feasibility and safety of endoscopic transesophageal biopsy by using submucosal tunneling technology novel homemade instruments in the posterior mediastinum.

METHODOLOGY: In six survival pigs, a mid-esophageal mucosal incision and a 10-cm submucosal tunnel was created. The endoscope attached to homemade decompression tube was passed through the muscular layers into the posterior mediastinal space. The mediastinal compartment, lung, descending thoracic aorta, vertebra, and exterior surface of the esophagus will be identified, and mediastinal living tissue as lymph node biopsy will also be accomplished. During two survival weeks, blood test and temperature monitoring and chest radiograph and endoscopic examination were performed.

RESULTS: The procedure was successfully completed in all six pigs. Mediastinal structures could be identified without difficulty by the transesophageal tunneling approach. Tissue as lymph nodes and pleural biopsy under direct visualization were easily accomplished. One pig died after operation due to an unexplained pneumothorax. At necropsy, apparent atelectasis was noted in the right lobe. After applying homemade drainage tube attached to the syringe, one pig with pneumothorax soon had restoration. There were no apparent ill effects in the survival pigs.

CONCLUSIONS: Endoscopic transesophageal biopsy in the posterior mediastinum using a novel tunneling technology can provide excellent visualization of mediastinal structures. These procedures could be performed safely in pigs with short-term survival. Further study about immediate complications will be needed with a larger sample size and longer survival time.